Weight loss is a common problem in patients with cancer, affecting their quality of life and their ability to respond to therapy. Total parenteral nutrition has not been able to reverse the body depletion phenomenon to the point where oncologist question the efficacy of its use in the cancer patient. On the other hand, insulin has been shown to improve food intake, nitrogen balance and body weight in wasting-state rats without stimulating tumor growth. Insulin treatment has also been shown to increase body cell mass, the fundamental structural component of animals. In rat studies, this improvement has led to improved survival following tumor resection. This study will evaluate 20 patients who have lost and least 10% of normal body weight, have biopsy proven cancer and are in an anorectic state. The patients also must have a functioning gastro-intestinal tract. The following questions will be investigated. 1. Can low-dose exogenous insulin improve body weight, cell mass, food intake, nitrogen balance and body catabolism of an anorectic patient with cancer? 2. Can exogenous insulin accomplish the above without developing dangerously low blood sugar levels? A whole body counter will be used to measure the K40 level of each patient. This measurement relates directly to the body cell mass. Resting energy expenditure will be determined and the metabolic kitchen will be utilized for a balance study.